JP2021077969A - Resin film for diaphragm of portable equipment speaker and method for manufacturing the same - Google Patents

Abstract

To provide a resin film for a diaphragm of a portable equipment speaker which can expect improvement of slipperiness even when being formed of a crystalline thermoplastic polyimide resin, and suppresses occurrence of resonance and can obtain good sound quality due to increase in a loss tangent, and a method for manufacturing the same.SOLUTION: A resin film 1 for a diaphragm is formed of a molding material 2 containing 100 pts.mass of a crystalline thermoplastic polyimide resin and 1 pts.mass or more and 100 pts.mass or less of an adhesive fluorine resin. The thermoplastic polyimide resin is prepared by at least a tetracarboxylic component and a diamine component mainly containing aliphatic diamine, and has maximum tensile strength at 23°C of 40 N/mm2 or more and tensile elongation at break of 100% or more, tensile elastic modulus at 23°C of 1,000 N/mm2 or more and 3,000 N/mm2 or less, a coefficient of static friction at 23°C of 0.50 or less, a coefficient of dynamic friction of 0.50 or less, and a loss tangent at 20°C of 0.014 or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to a resin film for a diaphragm of a portable device speaker used in a mobile phone, a portable game device, a smartphone, etc., and a method for manufacturing the same.

Mobile devices such as mobile phones and smartphones have a built-in small speaker called a micro speaker, and the diaphragm that generates sound waves from this speaker is an important component that affects sound quality. This diaphragm is manufactured using various materials such as metal leaf, paper, and woven cloth, but a resin film is used from the viewpoint of ensuring sound quality characteristics, rigidity, moisture resistance, water resistance, and heat resistance. Often.

Conventional resin films for vibrating plates of portable device speakers include polyolefin resins such as polyethylene (PE) resin and polypropylene (PP) resin, polyester resins such as polyethylene terephthalate (PET) resin and polyethylene naphthalate (PEN) resin. It is molded from a polyphenylene sulfide (PPS) resin, a polyetherimide (PEI) resin, a polyether ether ketone (PEEK) resin, or the like (see Patent Documents 1, 2, 3, and 4).

Further, in recent years, in order to secure high strength, heat resistance and the like, it has been proposed to use a crystalline thermoplastic polyimide (PI) resin. In this case, the resin film for the diaphragm of the portable device speaker is formed into a strip-shaped thin film by a crystalline thermoplastic polyimide resin, cooled, wound on a winder, and then unwound to be a speaker of the portable device. Secondary processing for use (see Patent Document 5).

Japanese Unexamined Patent Publication No. 60-139098 Japanese Unexamined Patent Publication No. 2019-054534 Japanese Unexamined Patent Publication No. 2018-191069 JP-A-2018-064150 JP-A-2018-042043

The conventional resin film for a vibrating plate of a portable device speaker is formed as described above, and when molded from a crystalline thermoplastic polyimide resin, it is excellent in high strength, high heat resistance, high solvent resistance, etc., but is sufficient. Since it is not possible to obtain smooth slipperiness, wrinkles may occur when the film is wound by a winder during manufacturing. As a result, there arises a problem that the resin film for the diaphragm is broken or damaged during manufacturing or secondary processing.

As a method for solving this problem, a method of adding a tetrafluoroethylene / perfluoroethylene copolymer resin to a crystalline thermoplastic polyimide resin to improve slipperiness has been proposed. In the case of this method, the slipperiness of the resin film obtained from the mixture of the crystalline thermoplastic polyimide resin and the tetrafluoroethylene / perfluoroalkoxyethylene copolymer resin is sufficiently improved as originally planned.

However, the resin film obtained from the mixture of the crystalline thermoplastic polyimide resin and the tetrafluoroethylene / perfluoroalkoxyethylene copolymer is a combination of the crystalline thermoplastic polyimide resin and the tetrafluoroethylene / perfluoroalkoxyethylene. Since the compatibility with the polymer resin is poor and the mechanical strength is reduced, if the external output is increased and the product is used at a high volume for a long period of time, the durability will deteriorate due to deformation or damage of the diaphragm of the portable device speaker. A new big problem arises.

Further, when the resin film for a vibrating plate is molded from a crystalline thermoplastic polyimide resin, the elastic modulus is low, so that the bass resonance frequency (F ₀ ) is low, and for example, the powerful deep bass that reverberates can be easily heard. It is possible to obtain sufficient bass characteristics. However, since the resin film for a vibrating plate made of a crystalline thermoplastic polyimide resin has a small loss positive tangent (= loss elastic modulus / storage elastic modulus, or tan δ), resonance occurs and good sound quality can be obtained. Is difficult. Further, since the crystalline thermoplastic polyimide resin film is inferior in slipperiness between the resin films, wrinkles may occur when the resin films are wound by the winder, resulting in deterioration of quality.

The present invention has been made in view of the above, and even if it is molded from a crystalline thermoplastic polyimide resin, it can be expected to improve slipperiness, and it is good to suppress the occurrence of resonance by increasing the loss tangent. It is an object of the present invention to provide a resin film for a diaphragm of a portable device speaker capable of obtaining sound quality and a method for manufacturing the same.

As a result of diligent research in order to achieve the above object, the present inventors have focused on the combination of a crystalline thermoplastic polyimide resin and an adhesive fluororesin, and completed the present invention.

That is, in order to solve the above problems in the present invention, the thermoplastic polyimide is molded from a molding material containing 100 parts by mass of a crystalline thermoplastic polyimide resin and 1 part by mass or more and 100 parts by mass or less of an adhesive fluororesin. The resin is prepared by at least a tetracarboxylic component and a diamine component containing an aliphatic diamine as a main component.
Maximum tensile strength at 23 ° C is 40 N / mm ² or more, elongation at tensile break is 100% or more, tensile elastic modulus at 23 ° C is 1000 N / mm ² or more and 3000 N / mm ² or less, and coefficient of static friction at 23 ° C is 0.50. It is characterized by having a dynamic friction coefficient of 0.50 or less and a loss tangent at 20 ° C. of 0.014 or more.

When an elastomer layer having a thickness of 10 μm or more and 100 μm or less is sandwiched between a pair of resin films for diaphragms, and the durometer hardness of the elastomer layer is measured by a durometer type A in accordance with JIS K 6253. In addition, it can be A10 or more and A90 or less.

The diamine component of the thermoplastic polyimide resin is preferably a linear aliphatic diamine having 4 or more and 12 or less carbon atoms.
Further, the diamine component of the crystalline thermoplastic polyimide resin may contain at least an alicyclic diamine.

The alicyclic diamine is preferably 1,3-bis (aminomethyl) cyclohexane.
Further, the apparent shear viscosity of the adhesive fluororesin at 350 ° C. is preferably 1 × 10 ² Pa · s or more and 1 × 10 ⁵ Pa · s or less when the load is 50 kgf.

Further, in the present invention, in order to solve the above problems, the method for manufacturing a resin film for a diaphragm of a portable device speaker according to any one of claims 1 to 4.
A molding material is prepared from 100 parts by mass of a crystalline thermoplastic polyimide resin and 1 part by mass or more and 100 parts by mass or less of an adhesive fluororesin, and the thermoplastic polyimide resin of this molding material is mixed with at least a tetracarboxylic component and an aliphatic component. Diamine is the main component of the diamine component
The molding material is melt-kneaded and put into an extrusion molding machine, and the molding material is extruded into a resin film for a diaphragm of a portable device speaker by a die of the extrusion molding machine, and the resin film for the diaphragm is brought into contact with a cooling roll. It is characterized in that the cooled resin film for a vibrating plate is then wound up by a winder.

Here, the resin film for the diaphragm of the portable device speaker in the claims includes a resin sheet in addition to the resin film. The resin film for the diaphragm of the portable device speaker is not particularly limited to transparent, opaque, translucent, non-stretched film, uniaxially stretched film, and biaxially stretched film. Further, the resin film for the diaphragm of the portable device speaker may be one sheet, but may be a plurality of sheets. In this case, for example, an elastomer layer is interposed between the resin films for the diaphragm of a pair of portable device speakers, and a primer for adhesion is provided between the resin film for the diaphragm of the portable device speaker and the elastomer layer. Layers can be intervened.

According to the present invention, since the molding material is prepared of a crystalline thermoplastic polyimide resin and an adhesive fluororesin, it is possible to obtain good sound quality characteristics in which loss tangent is increased and resonance is suppressed. Further, since the molding material contains a crystalline thermoplastic polyimide resin, it is possible to obtain a resin film for a diaphragm of a portable device speaker having excellent toughness, high heat resistance, high solvent resistance, bass characteristics and the like. Further, since it also contains an adhesive fluororesin having excellent dispersibility, excellent slipperiness can be obtained, and wrinkles are less likely to occur when the resin film for a diaphragm of a portable device speaker is wound up.

According to the present invention, even if it is molded from a crystalline thermoplastic polyimide resin, it is expected that the slipperiness will be improved, and the occurrence of resonance can be suppressed by increasing the loss tangent to obtain good sound quality. It has the effect of being able to do it.

According to the invention of claim 2, the durometer hardness of the elastomer layer is A10 or more and A90 or less when measured by the type A of the diaphragm in accordance with JIS K 6253. Therefore, the compression set characteristics of the elastomer layer. It is possible to prevent the problem of sound quality from being deteriorated or the vibration propagation speed of the diaphragm of the portable device speaker is lowered. In addition, it is possible to prevent the loss tangent from becoming small and the performance of the diaphragm from deteriorating.

According to the invention of claim 3, since the diamine component of the thermoplastic polyimide resin contains at least a linear aliphatic diamine having 4 or more and 12 or less carbon atoms, the moldability of the resin film for the diaphragm of the portable device speaker and the like. Next processability and low moisture absorption can be improved.
According to the invention of claim 4, the adhesive fluororesin can be uniformly dispersed in the crystalline thermoplastic polyimide resin, and the vibrating plate of the portable device speaker excellent in mechanical properties, slipperiness, and sound quality characteristics. It becomes possible to manufacture a resin film for use.

It is an overall explanatory view which shows typically the embodiment of the resin film for the diaphragm of the portable device speaker which concerns on this invention, and the manufacturing method thereof. It is explanatory drawing which shows typically the 2nd Embodiment of the resin film for the diaphragm of the portable device speaker which concerns on this invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the resin film 1 for the diaphragm of the portable device speaker in the present embodiment includes a crystalline thermoplastic polyimide resin and a crystalline thermoplastic polyimide resin. Extruded by a molding material 2 containing an adhesive fluororesin, a thermoplastic polyimide resin is prepared by at least a tetracarboxylic component and a diamine component containing an aliphatic diamine as a main component, and is used for a mobile phone microspeaker. Used for vibrating plates, etc.

The molding material 2 is prepared by containing 100 parts by mass of a crystalline thermoplastic polyimide (PI) resin and 1 part by mass or more and 100 parts by mass or less of an adhesive fluororesin. The molding material 2 includes a crystalline thermoplastic polyimide resin, an adhesive fluororesin, an antioxidant, a light stabilizer, an ultraviolet absorber, a plasticizer, a lubricant, and a flame retardant as long as the characteristics of the present invention are not impaired. , Antistatic agents, heat resistance improvers, inorganic compounds, organic compounds, resin modifiers and the like are selectively added.

The crystalline thermoplastic polyimide resin of the molding material 2 is obtained by polymerizing a tetracarboxylic acid component and a diamine component. Examples of the tetracarboxylic acid component of the thermoplastic polyimide resin include cyclobutane-1,2,3,4-tetracarboxylic dian, cyclopentane-1,2,3,4-tetracarboxylic acid, and cyclohexane-1,2,4,5. -Alicyclic tetracarboxylic acid such as tetracarboxylic acid, 3,3', 4,4'-diphenylsulfonetetracarboxylic acid, 3,3', 4,4'-benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, naphthalene Examples thereof include -1,4,5,8-tetracarboxylic acid and pyromellitic acid. Further, these alkyl esters can also be used.

Among these, it is preferable that the component exceeding 50 mol% of the tetracarboxylic acid component is pyromellitic acid. This is because if the tetracarboxylic dian component contains pyromellitic acid as the main component, the heat resistance, secondary processability, and low water absorption of the resin film 1 for the diaphragm of the portable device speaker are improved. From this point of view, the pyromellitic acid is preferably 60 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, among the tetracarboxylic acid components. In particular, it is optimal that all of the tetracarboxylic acid components (100 mol%) are pyromellitic acids.

It is important that the diamine component constituting the crystalline thermoplastic polyimide resin contains an aliphatic diamine (including an alicyclic diamine) as a main component. That is, it is important that the component exceeding 50 mol% of the diamine component is an aliphatic diamine, preferably 60 mol% or more, more preferably 80 mol% or more, and 90 mol% or more. It is particularly preferable to have. In particular, it is optimal that all of the diamine components (100 mol%) are aliphatic diamines. Since the main component is an aliphatic diamine, excellent heat resistance, low water absorption, moldability, and secondary processability can be imparted to the resin film 1 for a diaphragm of a portable device speaker.

The aliphatic diamine contained in the diamine component is not particularly limited as long as it is a diamine component having amine groups at both ends of the hydrocarbon group, but when heat resistance is important, the cyclic hydrocarbon can be used. It is preferable to contain an alicyclic diamine having an amine group at both ends. Specific examples of the alicyclic diamine include 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 4,4'-diaminodicyclohexylmethane, and 4,4'-methylenebis (2-). Methylcyclohexylamine), isophoronediamine, norbornandiamine, bis (aminomethyl) tricyclodecane and the like. Among these, 1,3-bis (aminomethyl) cyclohexane is most suitable from the viewpoint of achieving both heat resistance, moldability, and secondary processability.

When emphasizing the moldability and secondary processability of the resin film 1 for the diaphragm of a portable device speaker, a straight chain having amine groups at both ends of a linear hydrocarbon as an aliphatic diamine contained in the diamine component. It preferably contains an aliphatic diamine. The linear aliphatic diamine is not particularly limited as long as it is a diamine component having amine groups at both ends of the alkyl group, but specific examples thereof include ethylenediamine (2 carbon atoms) and propylene diamine (carbon). Number 3), butane diamine (4 carbons), pentandiamine (5 carbons), hexanediamine (6 carbons), heptanediamine (7 carbons), octanediamine (8 carbons), nonanediamine (9 carbons) , Decanediamine (10 carbons), undecanediamine (11 carbons), dodecanediamine (12 carbons), tridecanediamine (13 carbons), tetradecanediamine (14 carbons), pentadecanediamine (15 carbons), Hexadecanediamine (16 carbons), heptadecanediamine (17 carbons), octadecanediamine (18 carbons), nonadecandiamine (19 carbons), eikosan (20 carbons), triacantane (30 carbons), tetra Examples thereof include contan (40 carbon atoms) and pentacontan (50 carbon atoms).

Among these, a linear aliphatic diamine having 4 to 12 carbon atoms is most suitable from the viewpoint of excellent moldability, secondary processability, and low hygroscopicity. This linear aliphatic diamine may have a branched structure having 1 to 10 carbon atoms.

As a component other than the aliphatic diamine contained in the diamine component, another diamine component may be contained. Specifically, 1,4-phenylenediamine, 1,3-phenylenediamine, 2,4-toluenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, α, α'-bis (4-aminophenyl) ) 1,4'-Diisopropylbenzene, α, α'-bis (3-aminophenyl) -1,4-diisopropylbenzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 4,4 '-Diaminodiphenyl sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,6-diaminonaphthalene, 1,5-diaminonaphthalene, p- Examples include aromatic diamine components such as xylylene diamine and m-xylylene diamine, ether diamine components such as polyethylene glycol bis (3-aminopropyl) ether and polypropylene glycol bis (3-aminopropyl) ether, and siloxane diamines. ..

The diamine component may contain either or both of alicyclic diamine and linear aliphatic diamine, but since it has an excellent balance between heat resistance and moldability, alicyclic diamine and linear aliphatic diamine It is desirable to include both. When both alicyclic diamine and linear aliphatic diamine are contained, the respective contents may be in the range of alicyclic diamine: linear aliphatic diamine = 99: 1-1: 99 mol%. It is preferably 90:10 to 10:90 mol%, more preferably 80:20 to 20:80 mol%, and particularly preferably 70:30 to 30:70 mol%. The optimum ratio is 60:40 to 40:60 mol%. As long as the ratio of the alicyclic diamine and the linear aliphatic diamine contained in the diamine component is within the relevant range, the heat resistance and moldability of the resin film 1 for the diaphragm of the portable device speaker are in an excellent balance.

The melting point (also referred to as melting temperature) of the crystalline thermoplastic polyimide resin is 280 ° C. or higher and 370 ° C. or lower, preferably 300 ° C. or higher and 350 ° C. or lower, and more preferably 310 ° C. or higher and 330 ° C. or lower. This is because when the melting point of the crystalline thermoplastic polyimide resin is less than 280 ° C., the resin film 1 for the diaphragm of the portable device speaker having heat resistance cannot be obtained. On the other hand, when the melting point of the crystalline thermoplastic polyimide resin exceeds 370 ° C., the production temperature of the resin film 1 for the vibrating plate of the portable device speaker exceeds 400 ° C., so that the vibrating plate of the portable device speaker This is because it becomes difficult to manufacture the resin film 1 for use, and there arises a problem that the usable melt extrusion molding machine 10 is limited.

The glass transition point of the crystalline thermoplastic polyimide resin is preferably 160 ° C. or higher and 240 ° C. or lower, preferably 170 ° C. or higher and 210 ° C. or lower, and more preferably 170 ° C. or higher and 190 ° C. or lower. This is because when the glass transition point of the crystalline thermoplastic polyimide resin is less than 160 ° C., the resin film 1 for the diaphragm of the portable device speaker having heat resistance cannot be obtained. On the other hand, when the glass transition point of the crystalline thermoplastic polyimide resin exceeds 240 ° C., the melting point of the crystalline thermoplastic polyimide resin exceeds 370 ° C., and the resin film 1 for the diaphragm of the portable device speaker This is because the production temperature exceeds 400 ° C., which hinders the production of the resin film 1 for the diaphragm of the portable device speaker, and limits the usable melt extrusion molding machine 10.

The apparent shear viscosity of the crystalline thermoplastic polyimide resin is 1 × 10 ² Pa · s or more and 1 × 10 ⁴ Pa · s or less ^{when the apparent shear rate is 1 × 10 2} sec ^{-1 at a temperature of 350 ° C.} Within the range, preferably within the range of 5 × 10 ² Pa · s or more and 5 × 10 ³ Pa · s or less, more preferably within the range of 7 × 10 ² Pa · s or more and 1 × 10 ³ Pa · s or less. This is in the range where the apparent shear viscosity of the crystalline thermoplastic polyimide resin at a temperature of 350 ° C. and an apparent shear rate of 1 × 10 ² sec ^{-1 is 1 × 10 2} Pa · s or more and 1 × 10 ⁴ Pa · s or less. If it is inside, the dispersibility of the adhesive fluororesin in the crystalline thermoplastic polyimide resin becomes good, and the molding material 2 having excellent moldability of the resin film can be prepared. Further, it is based on the reason that a resin film 1 for a diaphragm having mechanical characteristics and sound quality characteristics suitable for a speaker of a portable device can be obtained.

As the crystalline thermoplastic polyimide resin, a random copolymer, an alternating copolymer, a block copolymer, or a modified product with another copolymerizable monomer is also used as long as the effect of the present invention is not impaired. be able to. Further, the shape of the crystalline thermoplastic polyimide resin may be any shape such as powder, flakes, pellets, and lumps.

The crystalline thermoplastic polyimide resin is not particularly limited, but preferably has the thermoplasticity described in Japanese Patent No. 5365762, Japanese Patent No. 6024859, Japanese Patent No. 6037088, or Japanese Patent No. 6394662. A polyimide resin, more preferably a thermoplastic polyimide resin described in Japanese Patent No. 6024859, Japanese Patent No. 6037088, or Japanese Patent No. 6394662 is preferable. Specific examples of this thermoplastic polyimide resin include the Surprim series [manufactured by Mitsubishi Gas Chemical Company: product name], which is excellent in high strength, high heat resistance, high solvent resistance, crystallinity, and film moldability.

Although the molding material 2 crystalline thermoplastic polyimide resin is used, which is by using the thermoplastic polyimide resin of the amorphous, tensile modulus of greater than 3000N / mm ^2, higher F ₀ value It is based on the reason that the bass characteristics deteriorate. Specific examples of the amorphous thermoplastic polyimide resin include polyetherimide resin. As this polyetherimide resin, a polycondensate of 4,4'-[isopropyridenebis (p-phenyleneoxy) diphthalic acid dianhydride and m-phenylenediamine [Product name: ULTEM 1010 manufactured by SABIC Innovative Plastics Co., Ltd.] ], Or a polycondensation polymer of 4,4'-[isopropyridenebis (p-phenyleneoxy) diphthalic acid dianhydride and p-phenylenediamine [Product name: ULTEM CRS5001 manufactured by SABIC Innovative Plastics Co., Ltd.].

The adhesive fluororesin has a repeating unit (a) based on tetrafluoroethylene (hereinafter referred to as TFE) and / or chlorotrifluoroethylene (hereinafter referred to as CTFE), a dicarboxylic acid anhydride group, and has a dicarboxylic acid anhydride group in the ring. A repeating unit (b) based on a cyclic hydrocarbon monomer having a polymerizable unsaturated group, and a repeating unit based on other monomers (however, if it overlaps with the repeating units (a) and (b), the monomer is excluded). Contains the unit (c).

In the adhesive fluororesin, the repeating unit (a) is 50 to 99.89 mol%, and the repeating unit (b) is 50 to 99.89 mol% with respect to the total molar amount of the repeating unit (a), the repeating unit (b), and the repeating unit (c). ) Is 0.01 to 5 mol%, and the repeating unit (c) is 0.1 to 49.99 mol%. The repeating unit (a) is preferably 50 to 99.47 mol%, the repeating unit (b) is 0.03 to 3 mol%, and the repeating unit (c) is 0.5 to 49.97 mol%, more preferably. The repeating unit (a) is 50 to 98.95 mol%, the repeating unit (b) is 0.05 to 2 mol%, and the repeating unit (c) is 1 to 49.95 mol%.

This is because the heat resistance and chemical resistance of the adhesive fluororesin are improved when the molar% of the repeating unit (a), the repeating unit (b), and the repeating unit (c) is in the relevant range. Further, when the molar% of the repeating unit (b) is in the range, the adhesive fluororesin is excellent in adhesiveness to the crystalline thermoplastic polyimide resin. Further, if the molar% of the repeating unit unit (c) is within the relevant range, the adhesive fluororesin is excellent in mechanical properties such as moldability and stress crack resistance.

The above-mentioned "cyclic hydrocarbon monomer having a dicarboxylic acid anhydride group and having a polymerizable unsaturated group in the ring" (hereinafter, simply abbreviated as cyclic hydrocarbon monomer) has one or more 5-membered rings or 6 A cyclic hydrocarbon composed of a member ring, and a polymerizable compound having a dicarboxylic acid anhydride group and an intracyclically polymerizable unsaturated group.

As the cyclic hydrocarbon, a cyclic hydrocarbon having one or more bridged polycyclic hydrocarbons is preferable. That is, a cyclic hydrocarbon composed of an Arihashi polycyclic hydrocarbon, a cyclic hydrocarbon obtained by condensing two or more of the Arihashi polycyclic hydrocarbons, or a cyclic hydrocarbon obtained by condensing an Arihashi polycyclic hydrocarbon with another cyclic hydrocarbon. It is preferable to have. Further, the cyclic hydrocarbon monomer has one or more polymerizable unsaturated groups in the ring, that is, one or more polymerizable unsaturated groups existing between the carbon atoms constituting the hydrocarbon ring. This cyclic hydrocarbon monomer further has a dicarboxylic acid anhydride group (-CO-O-CO-), and the dicarboxylic acid anhydride group may be bonded to two carbon atoms constituting the hydrocarbon ring, and the ring may be bonded. It may be bonded to two outer carbon atoms.

Preferably, the dicarboxylic acid anhydride group is a carbon atom constituting the ring of the cyclic hydrocarbon and is bonded to two adjacent carbon atoms. Further, a halogen atom, an alkyl group, an alkyl halide group, or another substituent may be bonded to the carbon atom constituting the ring of the cyclic hydrocarbon instead of the hydrogen atom. Specific examples include those represented by the following equations (1) to (8). Here, R in the formulas (2) and (5) to (8) is a halogen atom selected from a lower alkyl group having 1 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and the above lower grade. Indicates an alkyl halide group in which a hydrogen atom in an alkyl group is replaced with a halogen atom.

The cyclic hydrocarbon monomer is preferably 5-norbornene-2,3-dicarboxylic acid anhydride (hereinafter referred to as NAH) represented by the formula (1), represented by the formulas (3) and (4). Cyclic hydrocarbon monomers which are acid anhydrides, and cyclic hydrocarbon monomers whose substituent R is a methyl group in the formulas (2) and (5) to (8) can be mentioned. More preferably, NAH is good.

Examples of other monomers include vinyl fluoride, vinylidene fluoride (hereinafter referred to as VdF), CTFE (excluding the case where it is used as the repeating unit (a)), trifluoroethylene, and hexafluoropropylene (hereinafter referred to as HFP). ), CF ₂ = CFOR ^{f 1} (where R ^{f 1} is a perfluoroalkyl group having 1 to 10 carbon atoms and may contain oxygen atoms between carbon atoms), CF ₂ = CFOR ^{f 2} SO ₂ X ¹ (R ^{f) 2} is a perfluoroalkylene group having 1 to 10 carbon atoms and may contain an oxygen atom between carbon atoms, X ¹ is a halogen atom or a hydroxyl group), CF ₂ = CFOR ^{f 2} CO ₂ X ² (where R ^{f 2} is the above. Same as, X ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), CF ₂ = CF (CF ₂ ) _p OCF = CF ₂ (where p is 1 or 2), CH ₂ = CX ³ (CF) ₂ ) _q X ⁴ (where X ³ and X ⁴ are hydrogen atoms or fluorine atoms independently of each other, q is an integer of 2 to 10), perfluoro (2-methylene-4-methyl-1,3-dioxolane). ), Olefins having 2 to 4 carbon atoms such as ethylene, propylene and isobutene, vinyl esters such as vinyl acetate, vinyl ethers such as ethyl vinyl ether and cyclohexyl vinyl ether, and the like. Other monomers may be used alone or in combination of two or more.

Specific examples of the CF ₂ = CFOR ^{f 1,} for example, _{CF 2 = CFOCF 2 CF 3,} CF 2 = CFOCF 2 CF 2 CF 3, CF 2 = CFOCF 2 CF 2 CF 2 CF 3, CF 2 = CFO (CF 2 ) ₈ F, and the like. Preferably, CF ₂ = CFOCF ₂ CF ₂ CF ₃ . Further, _{as specific examples of CH 2} = CX ³ (CF ₂ ) _q X ⁴ , for example, CH ₂ = CH (CF ₂ ) ₂ F, CH ₂ = CH (CF ₂ ) ₃ F, CH ₂ = CH (CF _2). ) ₄ F, CH ₂ = CF (CF ₂ ) ₃ H, CH ₂ = CF (CF ₂ ) ₄ H and the like. Preferably, CH ₂ = CH (CF ₂ ) ₄ F or CH ₂ = CH (CF ₂ ) ₂ F.

Other monomers are preferably VdF, HFP, CTFE (except when used as a repeating unit (a)), CF ₂ = CFOR ^{f 1} , CH ₂ = CX ³ (CF ₂ ) _q X ⁴ , One or more selected from the group consisting of ethylene, propylene and vinyl acetate, more preferably HFP, CTFE (except when used as the repeating unit (a)), CF ₂ = CFOR ^{f 1} , ethylene. And CH ₂ = CX ³ (CF ₂ ) _q X ⁴ is one or more selected from the group. Most preferably, HFP or CF ₂ = CFOR ^f1 . Further, as CF ₂ = CFOR ^{f 1} , ^{a perfluoroalkyl group having R f 1} having 1 to 6 carbon atoms is preferable, a perfluoroalkyl group having 2 to 4 carbon atoms is more preferable, and a perfluoropropyl group is most suitable.

Specific examples of the adhesive fluororesin include, for example, TFE / CF ₂ = CFOCF ₂ CF ₂ CF ₃ / NAH copolymer, TFE / HFP / NAH copolymer, TFE / CF ₂ = CFOCF ₂ CF ₂ CF ₃ /. HFP / NAH copolymer, TFE / VdF / NAH copolymer, TFE / CH ₂ = CH (CF ₂ ) ₄ F / NAH / ethylene copolymer, TFE / CH ₂ = CH (CF ₂ ) ₂ F / NAH / Ethylene copolymer, CTFE / CH ₂ = CH (CF ₂ ) ₄ F / NAH / ethylene copolymer, CTFE / CH ₂ = CH (CF ₂ ) ₂ F / NAH / ethylene copolymer, CTFE / CH ₂ = CH (CF ₂ ) ₂ F / NAH / ethylene copolymer and the like.

The melting point of the adhesive fluororesin is preferably 150 ° C. or higher and 320 ° C. or lower, and more preferably 200 ° C. or higher and 310 ° C. or lower. The melting point can be adjusted by appropriately selecting the content ratios of the repeating unit (a), the repeating unit (b), and the repeating unit (c) within the above range.

If the polymer terminal group of the adhesive fluororesin has an adhesive functional group such as an ester group, a carbonate group, a hydroxyl group, a carboxyl group, a carbonyl fluoride group, or an acid anhydride residue, crystals other than the adhesive fluororesin It is preferable because it has excellent adhesion to a thermoplastic polyimide resin. Further, the polymer terminal group having an adhesive functional group can be introduced by appropriately selecting a radical polymerization initiator, a chain transfer agent, or the like at the time of producing the adhesive fluororesin.

The apparent shear viscosity of the adhesive fluororesin at a temperature of 350 ° C. is 1 × 10 ² Pa · s or more and 1 × 10 ⁵ Pa · s or less, preferably 7 × 10 ² Pa · s or more when a load of 50 kgf is applied. The range is 5 × 10 ⁴ Pa · s or less, more preferably 9 × 10 ² Pa · s or more and 2 × 10 ⁴ Pa · s or less. This is a portable device that can uniformly disperse the adhesive fluororesin in the crystalline thermoplastic polyimide resin if the apparent shear viscosity is within the range, and has excellent mechanical properties, slipperiness, and sound quality characteristics. This is because the production of the resin film 1 for the diaphragm of the speaker can be expected.

The method for producing the adhesive fluororesin is not particularly limited, but a radical polymerization method using a radical polymerization initiator is used. As this polymerization method, bulk polymerization, solution polymerization using an organic solvent such as fluorinated hydrocarbon, chlorinated hydrocarbon, fluorinated hydrocarbon, alcohol, hydrocarbon, aqueous medium and, if necessary, an appropriate organic solvent are used. Suspension polymerization used, emulsion polymerization using an aqueous medium and an emulsifier can be mentioned, but solution polymerization is particularly desirable.

The adhesive fluororesin is not particularly limited, but preferably the adhesive fluororesin described in Japanese Patent No. 4424246, Japanese Patent No. 5263269, Japanese Patent No. 5365939, or Japanese Patent Application Laid-Open No. 2019-43134. can give. Specific examples of this adhesive fluororesin include LH-8000 [manufactured by AGC: product name], AH-5000 [manufactured by AGC: product name], AH-2000 [manufactured by AGC: product name] EA-2000, and the like. [AGC: Product name] can be mentioned. Among these adhesive fluororesins, EA-2000, which has excellent heat resistance, is suitable.

The amount of the adhesive fluororesin added is 1 part by mass or more and 100 parts by mass or less, preferably 5 parts by mass or less and 90 parts by mass or less, and more preferably 10 parts by mass or more and 50 parts by mass with respect to 100 parts by mass of the crystalline thermoplastic polyimide resin. It is less than a part. This is because when the amount of addition is less than 1 part by mass, improvement in the loss and direct contact of the resin film 1 for the diaphragm of the speaker of the portable device cannot be expected, and conversely, when the amount of addition exceeds 100 parts by mass, it is portable. This is because the resin film 1 for the diaphragm of the device speaker is inferior in rigidity, so that the handleability during processing of the portable device speaker is lowered. From the above, if the amount of the adhesive fluororesin added is within the range of 1 part by mass or more and 100 parts by mass or less, the sound quality characteristics that suppress the occurrence of resonance are excellent, and the vibration of the portable device speaker that prevents the deterioration of handleability is prevented. A resin film 1 for a plate is obtained.

In addition to the above resins, the molding material 2 includes polyimide resins other than the above, such as polyimide (PI) resin, polyamideimide (PAI) resin, polyetherimide (PEI) resin, polyamide 4T (PA4T) resin, and polyamide 6T (PA6T). ) Resin, modified polyamide 6T (PA6T) resin, polyamide 9T (PA9T) resin, polyamide 10T (PA10T) resin, polyamide 11T (PA11T) resin, polyamide 6 (PA6) resin, polyamide 66 (PA66) resin, polyamide 46 (PA46) ) Polyene resin such as resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyester resin such as polyethylene naphthalate (PEN) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin , Polyetheretheretherketone (PEEEK) resin, polyetherketoneketone (PEKK) resin, polyetheretherketoneketone (PEEKK) resin, polyetherketone etherketoneketone (PEKEKK) resin, and other polyarylene etherketone resins, polysalphon ( PSU) resin, polyetherketone (PES) resin, polysulfone resin such as polyphenylsulphon (PPSU) resin, polyphenylene sulfide (PPS) resin, polyphenylene sulfide ketone resin, polyphenylene sulfide sulfone resin, polyphenylene sulfide ketone sulfone resin, etc. Polyetherylene sulfide resin, liquid crystal polymer (LCP), polycarbonate (PC) resin, poly allylate (PAR) resin and the like are added as needed.

In the above, when manufacturing the resin film 1 for the vibrating plate of the portable device speaker, for example, as shown in FIG. 1, first, the crystalline thermoplastic polyimide resin and the adhesive fluororesin are stirred and mixed at room temperature. After the molding material 2 is prepared by melting and kneading for a predetermined time, the resin film 1 for the diaphragm of the band-shaped portable device speaker is continuously molded by the molding material 2.

The method for preparing the molding material 2 is as follows: (1) A crystalline thermoplastic polyimide resin and an adhesive fluororesin are stirred and mixed at room temperature and then melt-kneaded to form a molding material for a resin film 1 for a diaphragm of a portable device speaker. Method 2 for adjusting, (2) Adhesive fluororesin is added to the molten crystalline thermoplastic polyimide resin without stirring and mixing the crystalline thermoplastic polyimide resin and the adhesive fluororesin, and these are added. A method of preparing the molding material 2 by melt-kneading can be mentioned. In the present invention, "room temperature" means 0 ° C. or higher and 50 ° C. or lower.

Any of these methods can be adopted, but the method (1) is preferable from the viewpoint of dispersibility and workability. First, the method (1) will be described. When the crystalline thermoplastic polyimide resin and the adhesive fluororesin are stirred and mixed, a tumbler mixer, a hessill mixer, a V-type mixer, a nouter mixer, and a ribbon blender are used. , Or a universal stirring mixer or the like is used.

The crystalline thermoplastic polyimide resin and the adhesive fluororesin are mixed by the above method, and the mixture is mixed with a mixing roll, a pressure kneader, a Banbury mixer, a planetary mixer, a twin-screw extruder, a triaxial extruder, and a quadruped extruder. It is prepared as a molding material 2 by being melt-kneaded and dispersed in a multi-screw extrusion molding machine such as a molding machine. When the molding material 2 is prepared, the temperature of the melt kneader is preferably 300 ° C. or higher and 400 ° C. or lower, preferably 330 ° C. or higher and 370 ° C. or lower. This is based on the reason that when the temperature of the melt extrusion molding machine 10 exceeds 400 ° C., the adhesive fluororesin is violently decomposed, which is not preferable.

Next, the method (2) will be described. In the case of this method, a crystalline thermoplastic polyimide resin is extruded by a mixing roll, a pressure kneader, a Banbury mixer, a planetary mixer, a twin-screw extruder, or a triaxial extruder. By melting with a multi-screw extruder such as a molding machine or a four-screw extrusion machine, adding an adhesive fluororesin to the thermoplastic polyimide resin, melt-kneading and dispersing it, the thermoplastic polyimide resin and the adhesive fluororesin can be obtained. The molding material 2 of the above is prepared. The temperature of the melt-kneader when preparing a composition composed of a thermoplastic polyimide resin and an adhesive fluororesin is preferably 300 ° C. or higher and 400 ° C. or lower, preferably 330 ° C. or higher and 370 ° C. or lower. This is because when the temperature of the melt extrusion molding machine 10 exceeds 400 ° C., the adhesive fluororesin decomposes violently as described above.

The molding material 2 is usually extruded into a lump, a strand, a sheet, or a rod, and then used in a form suitable for molding such as a powder, a granule, or a pellet by a crusher or a cutting machine.

The resin film 1 for a diaphragm of a portable device speaker made of the molding material 2 can be manufactured by a known method such as a melt extrusion molding method, a force render molding method, or a casting molding method. Here, the melt extrusion method is a molding material 2 of a crystalline thermoplastic polyimide resin and an adhesive fluororesin using a melt extrusion machine 10 including a single-screw extrusion machine, a twin-screw extrusion machine, and the like. Is melt-kneaded, and the resin film 1 for the diaphragm of the band-shaped portable device speaker is continuously extruded from the T-die 13 at the tip of the melt extrusion molding machine 10. From the viewpoint of handleability and simplification of equipment, the melt extrusion molding method is the most suitable method for manufacturing the resin film 1 for a diaphragm of a portable device speaker.

The melt extrusion molding machine 10 comprises, for example, a single-screw extrusion molding machine or a twin-screw extrusion molding machine, and functions to melt-knead the charged molding material 2. A raw material input port 11 for the molding material 2 is installed behind the upper part of the melt extrusion molding machine 10, and the raw material input port 11 has helium gas, neon gas, argon gas, krypton gas, nitrogen gas, and carbon dioxide gas. An inert gas supply pipe 12 for supplying an inert gas such as the above is connected, and the inflow of the inert gas through the inert gas supply pipe 12 is effective for oxidative deterioration and oxygen cross-linking of the molding material 2. Is prevented.

As the melt extrusion molding machine 10 such as a single-screw extrusion molding machine or a twin-screw extrusion molding machine, it is preferable to use the melt extrusion molding machine 10 having a vent port. This is because by melting and kneading under reduced pressure using the vent port, it becomes easy to sufficiently degas the water contained in the molding material 2 and the sublimated organic matter. Further, it is not necessary to adjust the water content of the molding material 2 before the melt-kneading.

The temperature at the time of melt-kneading of the melt extrusion molding machine 10 is a temperature at which the molding material 2 can be melted, and is not particularly limited as long as the molding material 2 does not decompose, but the temperature is equal to or higher than the melting point of the molding material 2. The range below the decomposition temperature is good. Specifically, the temperature is adjusted to 300 ° C. or higher and 400 ° C. or lower, preferably 330 ° C. or higher and 370 ° C. or lower. This is because if the temperature is lower than 300 ° C, the molding material 2 containing the thermoplastic polyimide resin cannot be melt-extruded, and if the temperature exceeds 400 ° C, the adhesive fluororesin may be severely decomposed. Because there is.

The molding material 2 melt-kneaded by the melt extrusion molding machine 10 is continuously extruded by the T-die 13 at the tip of the melt extrusion molding machine 10 onto the resin film 1 for the diaphragm of the band-shaped portable device speaker. It is manufactured by sandwiching a resin film 1 for a vibrating plate of a continuous portable device speaker between a pair of lower crimping rolls 17 and a cooling roll 18 to cool the film, and then winding the resin film 1 on a winder 20.

The T-die 13 is attached to the tip of the melt extrusion molding machine 10 via a connecting pipe 14 and functions to continuously push the resin film 1 for a diaphragm of a band-shaped portable device speaker downward. The temperature at the time of extrusion of the T-die 13 is in the range of the melting point of the molding material 2 or more and less than the thermal decomposition temperature. Specifically, the temperature is adjusted to 300 ° C. or higher and 400 ° C. or lower, preferably 330 ° C. or higher and 370 ° C. or lower. This is because if the temperature is lower than 300 ° C, the molding material 2 containing the crystalline thermoplastic polyimide resin cannot be melt-extruded, and conversely, if the temperature exceeds 400 ° C, the adhesive fluororesin is severely decomposed. This is because there is a risk of doing so.

It is preferable that the gear pump 15 and the filter 16 are respectively mounted on the connecting pipe 14 upstream of the T die 13. The gear pump 15 transfers the molding material 2 melt-kneaded by the melt extrusion molding machine 10 to the T-die 13 at a constant flow rate and with high accuracy through the filter 16. The filter 16 separates the gel, foreign matter, and the like of the molten molding material 2, and transfers the molten molding material 2 to the T die 13.

The pair of crimping rolls 17 are rotatably supported below the T-die 13 and sandwich the cooling roll 18 so as to be slidable, and the resin for the diaphragm of the portable device speaker is sandwiched between the pair of crimping rolls 17 and the cooling roll 18. The film 1 is sandwiched and cooled. Of the pair of crimping rolls 17, the take-up pipe 21 of the take-up machine 20 that winds up the resin film 1 for the diaphragm of the portable device speaker is rotatably installed further downstream of the downstream crimping roll 17 and crimped. A slit blade 22 that forms a slit on the side of the resin film 1 for the diaphragm of the portable device speaker is arranged between the roll 17 and the take-up pipe 21 of the take-up machine 20 so as to be able to move up and down. Between the blade 22 and the take-up pipe 21 of the take-up machine 20, a rotatable tension roll 19 is required for smoothly winding the resin film 1 for the diaphragm of the portable device speaker by applying tension. Be provided.

On the peripheral surface of each crimping roll 17, at least natural rubber, isoprene rubber, butadiene rubber, silicone rubber, fluororubber, etc. are used from the viewpoint of improving the adhesion between the resin film 1 for the vibrating plate of the portable device speaker and the cooling roll 18. A rubber layer is formed as needed, and an inorganic compound such as silica or alumina is selectively added to the rubber layer. Among these, it is preferable to use silicone rubber or fluororubber having excellent heat resistance.

As the crimping roll 17, a metal elastic roll having a metal surface is used as needed, and when this metal elastic roll is used, the resin film 1 for a diaphragm of a portable device speaker having an excellent surface smoothness. Molding becomes possible. Specific examples of the metal elastic roll include a metal sleeve roll, an air roll [manufactured by Dimco: product name], and a UF roll [manufactured by Hitachi Zosen Corporation: product name].

Such a crimping roll 17 is adjusted to a temperature of 50 ° C. or higher and 260 ° C. or lower, preferably 100 ° C. or higher and 240 ° C. or lower, more preferably 130 ° C. or higher and 220 ° C. or higher, and further preferably 150 ° C. or higher and 200 ° C. or lower, and is portable. The resin film 1 for the diaphragm of the device speaker is slidably contacted and pressed against the cooling roll 18. The temperature of the crimping roll 17 is within the range when the temperature of the crimping roll 17 exceeds 260 ° C., the resin film 1 for the diaphragm of the portable device speaker being manufactured is attached to the crimping roll 17, and the vibration of the portable device speaker is vibrated. This is because the resin film 1 for a plate may be broken, or the rubber layer coated and formed on the pressure-bonding roll 17 may be thermally decomposed.

On the contrary, when the temperature of the crimping roll 17 is less than 50 ° C., dew condensation occurs on the crimping roll 17, which is not preferable. Examples of the temperature adjusting and cooling method of the crimping roll 17 include a method using a heat medium such as air, water, and oil, an electric heater, a dielectric heating roll, and the like.

The cooling roll 18 is made of, for example, a metal roll having a diameter larger than that of the crimping roll 17, and the resin film 1 for the diaphragm of the portable device speaker rotatably supported and extruded below the T-die 13 is used as the crimping roll 17. The thickness of the resin film 1 for the diaphragm of the portable device speaker is controlled within a predetermined range while being sandwiched between the two and the crimping roll 17. Like the crimping roll 17, the cooling roll 18 has a temperature of 50 ° C. or higher and 260 ° C. or lower, preferably 100 ° C. or higher and 240 ° C. or lower, more preferably 130 ° C. or higher and 220 ° C. or higher, and further preferably 150 ° C. or higher and 200 ° C. or lower. It is adjusted and slides into the diaphragm resin film 1 of the portable device speaker.

The temperature of the cooling roll 18 is adjusted to 50 ° C. or higher and 260 ° C. or lower when the temperature of the cooling roll 18 exceeds 260 ° C. This is because the rubber layer of the crimping roll 17 may be thermally decomposed in the case of the crimping roll 17 in which the resin film 1 for the diaphragm of the portable device speaker is brought into close contact with the speaker or the rubber layer is coated and formed. .. On the other hand, if the temperature of the cooling roll 18 is less than 50 ° C., dew condensation is caused on the cooling roll 18, which is not preferable. Examples of the temperature adjustment and cooling method of the cooling roll 18 include a method using a heat medium such as air, water, and oil, an electric heater, induction heating, and the like.

In the above, when the resin film 1 for the diaphragm of the portable device speaker is manufactured more concretely and actually, as shown in FIG. 1, first, the molding material 2 is inserted into the raw material input port 11 of the melt extrusion molding machine 10. Is charged while supplying the inert gas shown by the arrow in the figure, and the crystalline thermoplastic polyimide resin and the adhesive fluororesin of the molding material 2 are melt-kneaded by the melt extrusion molding machine 10 and carried from the T die 13. The resin film 1 for the diaphragm of the equipment speaker is continuously extruded into a strip shape.

At this time, the water content of the molding material 2 before melt extrusion is adjusted to 2000 ppm or less, preferably 1000 ppm or less, and more preferably 100 ppm or more and 500 ppm or less. This is because when the water content exceeds 2000 ppm, the molding material 2 may foam immediately after being extruded from the T die 13.

After extruding the resin film 1 for the diaphragm of the portable device speaker, the resin film 1 is sequentially wound around the pair of crimping rolls 17, the cooling roll 18, the tension roll 19, and the take-up pipe 21 of the winder 20, and is used for the diaphragm of the portable device speaker. After cooling the resin film 1 with the cooling roll 18, both sides of the resin film 1 for the diaphragm of the portable device speaker are cut by the slit blades 22, and the resin film 1 is sequentially wound around the winding pipe 21 of the winding machine 20. A resin film 1 for a diaphragm of a portable device speaker can be manufactured. When the resin film 1 for the diaphragm of the portable device speaker is manufactured, fine irregularities are formed on the surface of the resin film 1 for the diaphragm of the portable device speaker within a range that does not lose the effect of the present invention. The coefficient of friction on the surface of the resin film 1 for a diaphragm can be reduced.

The thickness of the resin film 1 for the diaphragm of the portable device speaker is not particularly limited as long as it is 1 μm or more and 1000 μm or less, but it is preferable from the viewpoint of ensuring sufficient thickness, handleability, and thinning. It is preferably 3 μm or more and 100 μm or less, more preferably 4 μm or more and 97 μm or less, and further preferably 6 μm or more and 75 μm or less.

The relative crystallinity of the diaphragm resin film 1 of the portable device speaker is 80% or more, preferably 90% or more, more preferably 95% or more, still more preferably 100%. This is because when the relative crystallization degree of the diaphragm resin film 1 of the portable device speaker is less than 80%, there is a problem in the heat resistance of the diaphragm resin film 1 of the portable device speaker. Further, if the relative crystallinity is 80% or more, it can be expected to secure mechanical strength and heat resistance that can be used for a portable device speaker.

The crystallinity of the diaphragm resin film 1 of the portable device speaker can be expressed by the relative crystallinity. The relative crystallinity of the diaphragm resin film 1 of the portable device speaker is calculated by the following formula based on the thermal analysis result measured at a heating rate of 10 ° C./min using a differential scanning calorimeter.
Relative crystallinity (%) = {1- (ΔHc / ΔHm)} × 100
ΔHc: calorific value of recrystallization peak (J / g)
ΔHm: Calorific value of melting peak (J / g)

The mechanical properties of the resin film 1 for a diaphragm of a portable device speaker can be evaluated by the maximum tensile strength at 23 ° C., the elongation at tensile break, and the tensile elastic modulus. Maximum tensile strength, 40N / mm ² or more in the measurement method in conformity with JIS K 6781 and 7127, preferably 50 N / mm ² or more 200 N / mm ² or less, more preferably at 52N / mm ² or more 68N / mm ² or less .. Further, the elongation at tensile break is preferably 100% or more, preferably 150% or more and 300% or less, and more preferably 170% or more and 230% or less according to a measurement method based on JIS K 6781 or 7127.

This is because when the maximum tensile strength is ^{less than 40 N / mm 2} and the elongation at break is less than 100%, the resin film 1 for the diaphragm of the portable device speaker does not have sufficient toughness. This is because troubles such as breakage and cracking may occur during the processing of the resin film 1 for use, which makes the production difficult.
Tensile modulus at 23 ° C. of the diaphragm resin film 1 of the portable device speaker, 1000 N / mm ² or more in the measurement method in conformity with JIS K 6781 and JIS K 7127 3000N / mm ² or less, preferably 1250N / mm ² or more 2750N / mm ² or less, more preferably optimally 1400 N / mm ² or more 2250N / mm ² or less.

This is because when the tensile elastic modulus is ^{less than 1000 N / mm 2} , the resin film 1 for the diaphragm of the portable device speaker is inferior in rigidity and is easily deformed during processing of the portable device speaker, so that it is easy to handle. Is based on the reason that In addition, it is based on the reason that the bass characteristics cannot be improved. On the contrary, when it exceeds ^{3000 N / mm 2} _{, the F 0} value increases and the bass characteristic cannot be improved.

The coefficient of static friction of the resin film 1 for a diaphragm of a portable device speaker at 23 ° C. is 0.50 or less, preferably 0, from the viewpoint of obtaining excellent slipperiness when measured by a measuring method based on JIS K 7125-1999. .40 or less, more preferably 0.35 or less. The lower limit of the coefficient of static friction is not particularly limited, but is 0.04 or more in practical use. Further, the dynamic friction coefficient of the resin film 1 for a diaphragm of a portable device speaker at 23 ° C. is 0.50 or less, preferably 0.50 or less, from the viewpoint of obtaining excellent slipperiness when measured by a measuring method based on JIS K 7125-1999. It is preferably 0.40 or less, more preferably 0.30 or less. The lower limit of the dynamic friction coefficient is not particularly limited, but is 0.04 or more in practical use.

The loss tangent of the diaphragm resin film 1 of the portable device speaker at 20 ° C. is 0.014 or more, preferably 0.018 or more, more preferably 0.020 or more, and further, in order to prevent resonance and obtain good sound quality. Preferably 0.020 or more is optimal. This is because when the loss tangent is less than 0.015, good sound quality cannot be obtained due to the occurrence of resonance. The upper limit of the loss tangent is not particularly limited, but is preferably 0.45 or less.

Fine irregularities can be formed on the front and back surfaces of the resin film 1 for the diaphragm of the portable device speaker to reduce the friction coefficient. However, as a method for forming the fine irregularities, (1) fine irregularities are formed. A method of sandwiching a resin film 1 for a vibrating plate of a portable device speaker between a crimping roll 17 provided and a cooling roll 18 having fine irregularities to form fine irregularities, (2) a resin film for a vibrating plate of a portable device speaker. A method of spraying minute zirconia, glass, an inorganic compound such as stainless steel, a polycarbonate resin, a polyamide resin, or an organic compound such as a plant seed onto 1 to form fine irregularities, (3) a resin for a diaphragm of a portable device speaker. A method of press-molding the film 1 with a mold having fine irregularities to form fine irregularities can be mentioned. Among these methods, the method (1) is most suitable from the viewpoints of simplification of equipment, accuracy of unevenness size, uniform unevenness formation, ease of unevenness formation, and continuous unevenness formation. ..

Explaining the method (1) in more detail, (1-1) a molding material 2 composed of a crystalline thermoplastic polyimide resin and an adhesive fluororesin is subjected to fine irregularities from the T die 13 of the melt extrusion molding machine 10. While discharging on the cooling roll 18 provided on the peripheral surface, the discharged material is sandwiched between the cooling roll 18 and the crimping roll 17 provided on the peripheral surface, and melt extrusion of the resin film 1 for the diaphragm of the portable device speaker. Method of molding at the same time as molding, (1-2) The molded resin film 1 for the diaphragm of the portable device speaker is sandwiched between a crimping roll 17 having fine irregularities on the peripheral surface and a cooling roll 18 having fine irregularities. , A method of forming unevenness can be mentioned. Among these, the method (1-1) is preferable from the viewpoint of simplifying the equipment.

According to the above configuration, since the molding material 2 contains a crystalline thermoplastic polyimide resin, it is possible to obtain a resin film 1 for a diaphragm of a portable device speaker excellent in high strength, high heat resistance, high solvent resistance and the like. it can. Further, an adhesive fluororesin having excellent dispersibility is added to the molding material 2 to reduce the coefficient of static friction of the resin film 1 for the diaphragm of the portable device speaker to 0.260 or more and 0.350 or less, and to reduce the coefficient of dynamic friction. Since it is made as low as 0.160 or more and 0.290 or less, sufficient slipperiness can be obtained, and when the resin film 1 for the diaphragm of the portable device speaker is wound by the winder 20, wrinkles may occur. Absent. Therefore, it is possible to effectively solve the problem that the resin film 1 for the diaphragm of the portable device speaker is broken or damaged during manufacturing or secondary processing.

In addition, since an adhesive fluororesin having excellent compatibility with a crystalline thermoplastic polyimide resin is used instead of a fluororesin such as an ethylene tetrafluoride / perfluoroalkoxyethylene copolymer, it is a resin for a diaphragm of a portable device speaker. The film 1 can be smoothly produced by the melt extrusion molding method. Further, since the molding material 2 is prepared from a crystalline thermoplastic polyimide resin and an adhesive fluororesin, it is possible to obtain excellent sound quality characteristics in which loss tangent is increased and resonance is suppressed in addition to bass characteristics. it can. Therefore, it is possible to emphasize or reproduce important bass on the mobile device without relying on the software of the mobile device or connecting a dedicated external speaker to the mobile device.

Further, since the bass characteristics can be improved without making the speaker large and heavy, it is possible to contribute to the demand for thinning, downsizing, and weight reduction of the portable device. Further, since the resin film 1 for the diaphragm of the portable device speaker having a relative crystallinity of 80% or more, which is excellent in heat resistance, is used for the speaker, excellent heat resistance can be expected. Further, since the resin film 1 for a diaphragm containing a crystalline thermoplastic polyimide resin having excellent heat dissipation characteristics is used, the loss is reduced and the resin film 1 for a diaphragm of a portable device speaker can be used stably for a long period of time.

Next, FIG. 2 shows a second embodiment of the present invention. In this case, a resin film 1 for a diaphragm of a pair of portable device speakers is prepared, and for the diaphragm of the pair of portable device speakers. An elastomer layer 3 having a thickness of 10 μm or more and 100 μm or less is sandwiched and adhered between the resin films 1 to form a multilayer structure.

Examples of the elastomer of the elastomer layer 3 include silicone resin, urethane resin, acrylic resin, fluororesin, polyester resin, polyamide resin, hydrocarbon resin, styrene resin, vinyl chloride resin, vinyl acetate resin and the like. Among these elastomers, silicone resins, particularly heat-curable silicone resins, are preferable because they are excellent in heat resistance, weather resistance, flame retardancy, sound quality characteristics, compression characteristics and the like. Examples of the heat-curable silicone resin include an addition-curable mirable silicone resin and an addition-curable liquid silicone resin.

The addition-curable mirabable silicone resin is usually an organopolysiloxane, a silica-based filler, a curing agent (a curing agent combining a known platinum-based catalyst and an organohydrogenpolysiloxane, an organic oxide, or the like. ) And silica fine powder, etc. are used in the state of the composition to which various additives are added.

On the other hand, the addition-curable liquid silicone resin contains at least two organopolysiloxanes containing at least two alkenyl groups bonded to silicon atoms in one molecule and at least two hydrogen atoms bonded to silicon atoms in one molecule. Organohydrogenpolysiloxane and an inorganic filler (crushed diatomaceous soil, pearlite, foamed pearlite) having an average particle size of 1 μm or more and 30 μm or less and a bulk density of 0.1 g / cm ³ or more and 0.5 g / cm ^{3 or less.} , Mica, calcium carbonate, glass flakes, hollow filler, etc.) and addition reaction catalysts (platinum black, secondary platinum chloride, platinum chloride acid, reaction products of platinum chloride acid and monovalent alcohol, platinum chloride acid and olefins) It is used in the state of a resin composition to which a complex with, platinum bisacetoacetate, palladium-based catalyst, rhodium-based catalyst, etc.) is added.

The durometer hardness of the silicone resin when the silicone resin is used for the elastomer layer 3 is A10 or more and A90 or less, preferably A20 or more and A70 or less, more preferably, when measured by the durometer type A in accordance with JIS K 6253. The optimum range is A20 or more and A50 or less. This is because when the durometer hardness is less than A10, the compression set characteristics of the silicone resin layer deteriorate and the vibration propagation speed of the diaphragm decreases, causing a problem in sound quality. On the contrary, when the durometer hardness exceeds A90, the loss tangent becomes small and the performance of the diaphragm is deteriorated.

A multilayer structure in which a primer layer is interposed may be formed between the resin film 1 for the diaphragm of the pair of portable device speakers and the elastomer layer 3 for the purpose of firmly adhering them. Each primer is interposed between the elastomer layer 3 and the resin film 1 for the diaphragm of the portable device speaker, and functions to firmly bond them.

The primer is not particularly limited as long as it can adhere the silicone resin and the resin film 1 for the diaphragm of the portable device speaker, but is not particularly limited, and is, for example, an alkyd resin, an alkyd resin such as phenol-modified / silicone-modified. Examples thereof include modified products, oil-free alkyd resins, acrylic resins, silicone resins, epoxy resins, fluororesins, phenol resins, silane coupling agents, titanate-based coupling agents, aluminum-based coupling agents, and mixtures thereof. Examples of the cross-linking agent for curing and / or cross-linking these resins include isocyanate compounds, melamine compounds, epoxy compounds, peroxides, phenol compounds, hydrogen siloxane compounds, and silane compounds.

Each thin primer has a thickness of 0.1 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less. This is because when the thickness of the primer is less than 0.1 μm, the adhesion between the elastomer layer 3 and the resin film 1 for the diaphragm of the portable device speaker is insufficient, and during molding or use on the diaphragm. This is because there is a risk of peeling. On the other hand, if the thickness of the primer exceeds 5 μm, the secondary moldability to the diaphragm or the acoustic characteristics may be adversely affected.

In this embodiment as well, the same effects as those in the above embodiment can be expected, and the compression set characteristics of the elastomer layer 3 are deteriorated, and the vibration propagation speed of the diaphragm of the portable device speaker is lowered, so that there is a problem in sound quality. It is clear that it can be prevented from occurring.

Various elastomers such as various antistatic agents, silicone resin, acrylic resin, and urethane resin are applied to the surface of the resin film 1 for the vibrating plate of the portable device speaker of the above embodiment as long as the effect of the present invention is not lost. Alternatively, various metals such as aluminum, tin, nickel and copper may be deposited. Further, a plurality of disks, meshes, etc. of the filter 16 are selectively used by laminating as needed. Further, the opening shape of the filter 16 is not particularly limited to a circular shape, an elliptical shape, a rectangular shape, a polygonal shape, or the like.

Hereinafter, examples of a resin film for a diaphragm of a portable device speaker and a method for manufacturing the same according to the present invention will be described together with comparative examples.
[Example 1]
First, a molding material was prepared from a crystalline thermoplastic polyimide resin and an adhesive fluororesin. As a crystalline thermoplastic polyimide resin, 100 parts by mass of commercially available surprim TO-65 [manufactured by Mitsubishi Gas Chemical Company: product name, (hereinafter abbreviated as "TO-65")] is prepared, and this crystallinity The thermoplastic polyimide resin of No. 1 was dried for 12 hours in a dehumidifying dryer heated to 160 ° C. As the adhesive fluororesin, 5 parts by mass of a commercially available adhesive fluororesin EA-2000 [manufactured by AGC: product name, hereinafter abbreviated as "EA-2000"] was prepared. The apparent shear viscosity of the thermoplastic polyimide resin and the adhesive fluororesin was evaluated by the apparent shear viscosity at a temperature of 350 ° C.

After preparing these, two kinds of resins are put into a mixer and stirred and mixed to prepare a stirring mixture, and this stirring mixture is melt-kneaded by a co-rotating twin-screw extruder or the like and extruded into a strand shape. This extruded product was water-cooled and solidified, and then cut into pellets to prepare a molding material. As the co-rotating twin-screw extruder, a φ25 mm, L / D = 41 type was used. The stirring mixture was melt-kneaded under the conditions of a cylinder temperature of 200 to 350 ° C. and a die temperature of 350 ° C. to prepare a molding material. The temperature at the time of melt-kneading was determined to be the temperature of the molded material in the molten state immediately after being extruded from the die, and the measured temperature was 368 ° C.

Next, the molding material was put into a dehumidifying / drying machine heated to 160 ° C. and dried for 24 hours, and the dried molding material was put into a single-screw extrusion molding machine with a T-die having a width of 150 mm for melt-kneading, and this melt-kneading was performed. The molded material was continuously extruded from the T-die, and the resin film for the diaphragm of the portable device speaker was extruded into a strip shape. The single-screw extruder was of the type having a diameter of 20 mm and a screw: full flight screw (L / D = 25, compression ratio: 2.5). The temperature of the single-screw extruder was adjusted to 340 to 350 ° C., the temperature of the T-die was adjusted to 350 ° C., and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 350 ° C. Regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 351 ° C.

After the resin film for the vibrating plate of the portable device speaker is extruded in this way, the resin film for the vibrating plate of the portable device speaker is formed into a pair of crimping rolls made of silicone rubber as shown in FIG. 1 and a metal which is a cooling roll at 150 ° C. The rolls and the 3-inch take-up pipes of the take-up machine located downstream of these are sequentially wound, and sandwiched between the crimping roll and the metal roll, and both sides of the resin film for the vibrating plate of the continuous portable device speaker. Was cut with a slit blade and sequentially wound around a take-up tube to produce a resin film for a diaphragm of a portable device speaker having a length of 10 m and a width of 130 mm.

After manufacturing the resin film for the diaphragm of the portable device speaker, the film thickness, mechanical properties, slipperiness, acoustic characteristics of the resin film for the diaphragm of the portable device speaker, and the winding wrinkles when wound on the winding tube It was decided to measure the occurrence, summarize it in Table 1, and evaluate it. The mechanical characteristics are the maximum tensile strength of the resin film for the diaphragm of the portable device speaker, the elongation at tensile break, and the tensile elastic modulus, and the slipperiness is the static friction coefficient and the dynamic friction coefficient of the resin film for the diaphragm of the portable device speaker, and the acoustic characteristics. It was evaluated by the loss tangent.

-Apparent shear viscosity of crystalline thermoplastic polyimide resin The apparent shear viscosity of crystalline thermoplastic polyimide resin is determined by drying the crystalline thermoplastic polyimide resin at 160 ° C for 24 hours and then using the Twin Capillary Leometer R6000. It was measured using [Product name manufactured by IMATEK]. Specifically, a crystalline thermoplastic polyimide resin under the conditions of capillary die: φ1.0 mm × 16 mm (long die), φ1.0 mm × 0.25 mm (short die), barrel diameter: 15 mm, and temperature: 350 ° C. 40g into the barrel, push the piston at a speed of 50mm / min until the long die side: 0.9MPa and the short die side: 0.3MPa, and when the pressure reaches the specified value, leave it as it is for 6 minutes. Retained.

After that, push the piston again at a speed of 50 mm / min until the long die side: 0.9 MPa and the short die side: 0.3 MPa, and when the pressure reaches a predetermined value, the predetermined apparent shear rate (1 × 10 ^1). , 2 × 10 ¹ , 3 × 10 ¹ , 5 × 10 ¹ , 8 × 10 ¹ , 1 × 10 ² , 3 × 10 ² , 8 × 10 ² sec ^-1 ) I asked. As the apparent shear viscosity of the crystalline thermoplastic polyimide resin, the apparent shear viscosity of the crystalline thermoplastic polyimide resin was determined when the apparent shear rate was 1 × 10 ² sec ^-1.

-Apparent Shear Viscosity of Adhesive Fluororesin The apparent shear viscosity of the adhesive fluororesin at a temperature of 350 ° C. was measured using a flow tester. Specifically, resin 1.5 cm ³ is filled in a cylinder at 350 ° C. mounted on a die (diameter: 1 mm, length 10 mm), and a plunger having ^{an area of 1.0 cm 2 is attached to the upper part of this cylinder.} When the temperature of the cylinder reached 350 ° C., preheating was performed for 5 minutes, and immediately after this preheating, a load of 50 kgf was applied to melt and flow out the adhesive fluororesin, and the apparent shear viscosity was measured. The measurement was performed three times, and the average value was taken as the apparent shear viscosity.

-Thickness of resin film for diaphragm of portable device speaker The film thickness of resin film for diaphragm of portable device speaker is measured using a micrometer [Product name manufactured by Mitutoyo Co., Ltd .: Coolant proof micrometer code MDC-25PJ]. did. At the time of measurement, the central portion of the resin film for the diaphragm of the portable device speaker in the width direction (direction perpendicular to the extrusion direction) was measured at any five points facing the extrusion direction, and the average value was taken as the film thickness.

-Mechanical properties of the resin film for the diaphragm of the portable device speaker The mechanical properties of the resin film for the diaphragm of the portable device speaker are evaluated by measuring the maximum tensile strength, elongation at tensile break, and tensile elastic modulus. did. Specifically, in accordance with JIS K 6251, measurements were taken in the extrusion direction and the width direction under the conditions of a tensile speed of 50 mm / min, a temperature of 23 ° C. ± 2 ° C., and a relative humidity of 50% RH ± 5% RH. As the test piece, JIS K6251 type 2 was used. The measurement was performed 5 times, and the average value was taken as the maximum tensile strength, elongation at tensile break, and tensile elastic modulus.

-Slipperiness of the resin film for the diaphragm of the portable device speaker The slipperiness of the resin film for the diaphragm of the portable device speaker was evaluated by measuring the static friction coefficient and the dynamic friction coefficient. These static friction coefficient and dynamic friction coefficient were measured according to JIS K7125-1999. Specifically, using a surface measuring machine [Product name: HEDON-14 manufactured by Shinto Kagaku Co., Ltd.], the test speed: 100 mm / min in an environment of 23 ° C ± 2 ° C and 50% RH ± 5% RH. , Load: 200 g, contact area: 63.5 mm × 63.5 mm.

Then, the outer surface of the resin film for the diaphragm of the portable device speaker is fixed to the moving table side, the inner surface of the resin film for the diaphragm is fixed to the fixed table side, and a load of 200 g is applied to the surface to apply a load of 100 mm / min. The coefficient of static friction and the coefficient of dynamic friction were measured at velocities, respectively.

-Acoustic characteristics of the resin film for the diaphragm of the portable device speaker The acoustic characteristics of the resin film for the diaphragm of the portable device speaker were evaluated by measuring the loss tangent at 20 ° C. This loss tangent was measured in the extrusion and width directions. Specifically, when measuring the loss tangent in the extrusion direction of the resin film, the size is 60 mm in the extrusion direction × 6 mm in the width direction, and when measuring the loss tangent in the width direction, the size is 6 mm in the extrusion direction × 60 mm in the width direction. It was cut out and measured. When measuring the loss tangent, the frequency is 1 Hz, the strain is 0.1%, and the temperature rise rate is 3 by the tension mode using a viscoelastic spectrometer (product name: RSA-G2 manufactured by TS Instruments Japan). The measurement was performed under the conditions of ° C./min, measurement temperature range -60 ° C. to 360 ° C., and check interval 21 mm, and a loss tangent at 20 ° C. was determined.

・ Occurrence of wrinkles when winding the resin film for the diaphragm of the portable device speaker during manufacturing When the resin film for the diaphragm of the portable device speaker is manufactured, the wrinkles when winding the resin film for the diaphragm of the portable device speaker The presence or absence of the occurrence was marked with XX by visually observing after winding 100 m on the take-up pipe. ○ indicates that there is no wrinkle, and × indicates that there is wrinkle.

[Example 2]
In Example 1, a crystalline thermoplastic polyimide resin [Surprim TO-65] dried at 160 ° C. for 24 hours and an adhesive fluororesin of Example 1 [Product name: EA-2000] were prepared and adhered. The fluororesin is weighed so as to be 10 parts by mass with respect to 100 parts by mass of the crystalline thermoplastic polyimide resin, and then the two types of resins are put into a mixer and stirred and mixed at room temperature for 1 hour to stir. A mixture was prepared.

Hereinafter, the stirring mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material in the same manner as in Example 1. Regarding the temperature at the time of melt-kneading the crystalline thermoplastic polyimide resin and the adhesive fluororesin, the temperature of the molded material in the molten state immediately after being extruded from the die was measured, and the measured temperature was 363 ° C.

Next, the molding material dried at 160 ° C. for 24 hours was put into the φ20 mm single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melt-kneaded, and the melt-kneaded molding material was melt-kneaded from the T-die. The resin film for the diaphragm of the portable device speaker was extruded into a strip shape by continuously extruding. Regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 350 ° C.

After the resin film for the diaphragm of the portable device speaker is extruded in this way, the resin film for the diaphragm is sequentially wound around the take-up tube by the same method as in the first embodiment, so that the portable device has a length of 10 m and a width of 120 mm. A resin film for a speaker diaphragm was manufactured. After manufacturing the resin film for the diaphragm of the portable device speaker, the film thickness, mechanical properties, slipperiness, acoustic characteristics of the resin film for the diaphragm of the portable device speaker, and the winding wrinkles when wound on the winding tube Occurrences were measured, listed in Table 1 and evaluated.

[Example 3]
In Example 1, a crystalline thermoplastic polyimide resin [Surprim TO-65] dried at 160 ° C. for 24 hours and an adhesive fluororesin of Example 1 [Product name: EA-2000] were prepared and adhered. The fluororesin is weighed so as to be 20 parts by mass with respect to 100 parts by mass of the crystalline thermoplastic polyimide resin, and then the two types of resins are put into a mixer and stirred and mixed at room temperature for 1 hour to stir. A mixture was prepared.

Hereinafter, the stirring mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material in the same manner as in Example 1. Regarding the temperature at the time of melt-kneading the crystalline thermoplastic polyimide resin and the adhesive fluororesin, the temperature of the molded material in the molten state immediately after being extruded from the die was measured, and the measured temperature was 366 ° C.

Next, the molding material dried at 160 ° C. for 24 hours was put into the φ20 mm single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melt-kneaded, and the melt-kneaded molding material was melt-kneaded from the T-die. The resin film for the diaphragm of the portable device speaker was extruded into a strip shape by continuously extruding. Regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 354 ° C.

After the resin film for the diaphragm of the portable device speaker is extruded in this way, the resin film for the diaphragm is sequentially wound around the take-up tube by the same method as in the first embodiment, so that the portable device has a length of 10 m and a width of 120 mm. A resin film for a speaker diaphragm was manufactured. After manufacturing the resin film for the diaphragm of the portable device speaker, the film thickness, mechanical properties, slipperiness, acoustic characteristics of the resin film for the diaphragm of the portable device speaker, and the winding wrinkles when wound on the winding tube Occurrences were measured, listed in Table 1 and evaluated.

[Example 4]
In Example 1, a crystalline thermoplastic polyimide resin [Surprim TO-65] dried at 160 ° C. for 24 hours and an adhesive fluororesin of Example 1 [Product name: EA-2000] were prepared and adhered. The fluororesin is weighed so as to be 50 parts by mass with respect to 100 parts by mass of the crystalline thermoplastic polyimide resin, and then the two types of resins are put into a mixer and stirred and mixed at room temperature for 1 hour to stir. A mixture was prepared.

Hereinafter, the stirring mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material in the same manner as in Example 1. Regarding the temperature at the time of melt-kneading the crystalline thermoplastic polyimide resin and the adhesive fluororesin, the temperature of the molded material in the molten state immediately after being extruded from the die was measured, and the measured temperature was 365 ° C.

Next, the molding material dried at 160 ° C. for 24 hours was put into the φ20 mm single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melt-kneaded, and the melt-kneaded molding material was melt-kneaded from the T-die. The resin film for the diaphragm of the portable device speaker was extruded into a strip shape by continuously extruding. Regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 353 ° C.

After the resin film for the diaphragm of the portable device speaker is extruded, the resin film for the diaphragm is sequentially wound around the take-up tube by the same method as in the first embodiment, so that the portable device speaker having a length of 10 m and a width of 120 mm is sequentially wound. Manufactured a resin film for a diaphragm. After manufacturing the resin film for the diaphragm of the portable device speaker, the film thickness, mechanical properties, slipperiness, acoustic characteristics of the resin film for the diaphragm of the portable device speaker, and the winding wrinkles when wound on the winding tube Occurrences were measured, listed in Table 1 and evaluated.

[Example 5]
In Example 1, a crystalline thermoplastic polyimide resin [Surprim TO-65] dried at 160 ° C. for 24 hours and an adhesive fluororesin of Example 1 [Product name: EA-2000] were prepared and adhered. After weighing the fluororesin so as to be 90 parts by mass with respect to 100 parts by mass of the crystalline thermoplastic polyimide resin, the two types of resins are put into a mixer and stirred and mixed at room temperature for 1 hour to obtain a stirred mixture. Was prepared.

Hereinafter, the stirring mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material in the same manner as in Example 1. Regarding the temperature at the time of melt-kneading the crystalline thermoplastic polyimide resin and the adhesive fluororesin, the temperature of the molded material in the molten state immediately after being extruded from the die was measured, and the measured temperature was 363 ° C.

Next, the molding material dried at 160 ° C. for 24 hours was put into the φ20 mm single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melt-kneaded, and the melt-kneaded molding material was melt-kneaded from the T-die. The resin film for the diaphragm of the portable device speaker was extruded into a strip shape by continuously extruding. Regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 353 ° C.

After the resin film for the diaphragm of the portable device speaker is extruded, the resin film for the diaphragm is sequentially wound around the take-up tube by the same method as in the first embodiment, so that the portable device speaker having a length of 10 m and a width of 120 mm is sequentially wound. Manufactured a resin film for a diaphragm. After manufacturing the resin film for the diaphragm of the portable device speaker, the film thickness, mechanical properties, slipperiness, acoustic characteristics of the resin film for the diaphragm of the portable device speaker, and the winding wrinkles when wound on the winding tube The outbreak was measured, listed in Table 2 and evaluated.

[Comparative Example 1]
The molding material was changed to only crystalline thermoplastic polyimide resin. As the crystalline thermoplastic polyimide resin, 100 parts by mass of TO-65 used in Example 1 was prepared, and the crystalline thermoplastic polyimide resin was dried for 12 hours in a dehumidifying dryer heated to 160 ° C. .. After the crystalline thermoplastic polyimide resin was prepared and dried in this way, the crystalline thermoplastic polyimide was put into the φ20 mm single-screw extruder with a T-die having a width of 150 mm used in Example 1 and melt-kneaded. The melt-kneaded molding material was continuously extruded from the T-die to extrude a resin film for a diaphragm of a portable device speaker into a strip shape.

After the resin film for the vibrating plate of the portable device speaker is extruded, the resin film for the vibrating plate is subjected to a pair of crimping rolls made of silicone rubber as shown in FIG. 1, a metal roll which is a cooling roll at 150 ° C., and these. Along with sequentially winding on the 3-inch take-up pipe of the take-up machine located downstream, the resin film for the vibrating plate of the continuous portable device speaker is sequentially wound on the take-up pipe by being sandwiched between the crimping roll and the metal roll. As a result, a resin film for a diaphragm of a portable device speaker having a length of 10 m and a width of 120 mm was produced.

After manufacturing the resin film for the diaphragm of the portable device speaker for comparison, the film thickness, mechanical properties, slipperiness, acoustic characteristics, and winding of the resin film for the diaphragm of this portable device speaker when wound on a take-up tube. The occurrence of wrinkles was measured, listed in Table 3, and evaluated.

[Comparative Example 2]
First, a crystalline thermoplastic polyimide resin dried at 160 ° C. for 24 hours in Example 1 and EA-2000, which is an adhesive fluororesin of Example 1, are prepared, and the adhesive fluororesin is made into a crystalline thermoplastic. The mixture was weighed so as to be 150 parts by mass with respect to 100 parts by mass of the polyimide resin, and then the two kinds of resins were put into a mixer and stirred and mixed at room temperature for 1 hour to prepare a stirring mixture.

Hereinafter, the stirring mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material in the same manner as in Example 1. Regarding the temperature at the time of melt-kneading the crystalline thermoplastic polyimide resin and the adhesive fluororesin, the temperature of the molded material in the molten state immediately after being extruded from the die was measured, and the measured temperature was 346 ° C.

Next, the molding material dried at 160 ° C. for 24 hours was put into the φ20 mm single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melt-kneaded, and the melt-kneaded molding material was melt-kneaded from the T-die. The resin film for the diaphragm of the portable device speaker was extruded into a strip shape by continuously extruding. Further, regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 353 ° C.

After the resin film for the vibrating plate of the portable device speaker is extruded, the resin film for the vibrating plate is subjected to a pair of crimping rolls made of silicone rubber as shown in FIG. 1, a metal roll which is a cooling roll at 150 ° C., and these. Along with sequentially winding on the 3-inch take-up pipe of the take-up machine located downstream, the resin film for the vibrating plate of the continuous portable device speaker is sequentially wound on the take-up pipe by being sandwiched between the crimping roll and the metal roll. As a result, a resin film for a diaphragm of a portable device speaker having a length of 10 m and a width of 120 mm was produced.

After manufacturing the resin film for the diaphragm of the portable device speaker for comparison, the film thickness, mechanical properties, slipperiness, acoustic characteristics, and winding of the resin film for the diaphragm of this portable device speaker when wound on a take-up tube. The occurrence of wrinkles was measured, listed in Table 3, and evaluated.

[Comparative Example 3]
First, a crystalline thermoplastic polyimide resin dried at 160 ° C. for 24 hours in Example 1 and a fluororesin tetrafluoride / perfluoroalkoxyethylene copolymer having no adhesiveness (hereinafter, “PFA resin”). The molding material was prepared by (abbreviated as). As the PFA resin, a commercially available Neophron AP-210 [manufactured by Daikin Industries, Ltd .: product name, (hereinafter abbreviated as "AP-210")] was used. 15 parts by mass of this PFA resin was prepared with respect to 100 parts by mass of the crystalline thermoplastic polyimide resin. After preparing these, two kinds of resins were put into a mixer and mixed to prepare a stirring mixture. The apparent shear viscosity of the AP-210 at a temperature of 350 ° C. was measured by the same method as the measurement of the apparent shear viscosity of the adhesive fluororesin of Example 1.

After preparing the stirred mixture, the stirred mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material by the same method as in Example 1. The kneading temperature was determined to be the temperature of the molded material in the molten state immediately after being extruded from the die, and was measured to be 346 ° C.

Next, the molding material dried at 160 ° C. for 24 hours was put into the φ20 mm single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melt-kneaded, and the melt-kneaded molding material was melt-kneaded from the T-die. The resin film for the diaphragm of the portable device speaker was extruded into a strip shape by continuously extruding. Further, regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 353 ° C.

After manufacturing the resin film for the diaphragm of the portable device speaker, the film thickness, mechanical properties, slipperiness, acoustic characteristics of the resin film for the diaphragm of the portable device speaker, and the winding wrinkles when wound on the winding tube It was decided to measure the occurrence, list it in Table 3, and evaluate it.

[Comparative Example 4]
First, a molding material was prepared from an amorphous thermoplastic polyimide resin and an adhesive fluororesin. As the amorphous thermoplastic polyimide resin, a polyetherimide resin [4,4'-[polycondensation of isopropyridenebis (P-phenyloxy) diphthalic acid dianhydride and m-phenylenediamine] was used. .. As the amorphous thermoplastic polyetherimide resin, a commercially available ULTEM 1010-1000-NB [manufactured by SABIC: product name, (hereinafter abbreviated as "1010")] was used. 100 parts by mass of this 1010 was prepared, and the 1010 was dried for 12 hours in a dehumidifying dryer heated to 160 ° C. The apparent shear viscosity of 1010 at 350 ° C. was measured in the same manner as the crystalline thermoplastic polyimide resin of Example 1.

As the adhesive fluororesin, 10 parts by mass of EA-2000 used in Example 1 was prepared. After preparing these, a stirring mixture was prepared by putting two kinds of resins into a mixer and stirring and mixing them. After preparing the stirred mixture in this way, the stirred mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material by the same method as in Example 1. The kneading temperature was determined to be the temperature of the molded material in the molten state immediately after being extruded from the die, and was measured to be 346 ° C.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 24 hours, and the dried molding material was put into the single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melted. After kneading, the melt-kneaded molding material was continuously extruded from the T-die to extrude a resin film for a diaphragm of a portable device speaker having a width of 130 mm and a length of 10 m into a strip shape. The single-screw extruder and T-die used the same equipment as in Example 1. The temperature of the single-screw extruder was adjusted to 340 to 360 ° C., the temperature of the T-die was adjusted to 360 ° C., and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 360 ° C. It was decided to measure the resin temperature at the inlet of the T-dice, and the measured temperature was 361 ° C.

After manufacturing the resin film for the diaphragm of the portable device speaker, the film thickness, mechanical properties, slipperiness, acoustic characteristics of the resin film for the diaphragm of the portable device speaker, and the winding wrinkles when wound on the winding tube It was decided to measure the occurrence, list it in Table 3, and evaluate it.

[Comparative Example 5]
Thermoplastic polyimide resin is changed from crystalline thermoplastic polyimide resin to commercially available non-crystalline thermoplastic polyimide resin polyetherimide resin [4,4'-[isopropyridenebis (P-phenyloxy) diphthalic acid dianhydride] And p-phenylenediamine, polycondensate, manufactured by SABIC, product name: ULTEM CRS5001-1000-NB, (hereinafter abbreviated as "CRS5001").

100 parts by mass of this CRS5001 was prepared, and this 5001 was dried for 12 hours in a dehumidifying dryer heated to 160 ° C. The apparent shear viscosity of 5001 at 350 ° C. was measured in the same manner as the crystalline thermoplastic polyimide resin of Example 1. As the adhesive fluororesin, 10 parts by mass of EA-2000 used in Example 1 was prepared. After preparing these, a stirring mixture was prepared by putting two kinds of resins into a mixer and stirring and mixing them.

After preparing the stirred mixture, the stirred mixture was put into the co-rotating twin-screw extruder used in Example 1 to prepare a molding material by the same method as in Example 1. The stirring mixture was melt-kneaded under the conditions of a cylinder temperature of 200 to 360 ° C. and a die temperature of 360 ° C. to prepare a molding material. The temperature at the time of melt-kneading was determined to be the temperature of the molded material in the molten state immediately after being extruded from the die, and the measured temperature was 364 ° C.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 24 hours, and the dried molding material was put into the single-screw extrusion molding machine with a T-die having a width of 150 mm used in Example 1 and melted. After kneading, the melt-kneaded molding material was continuously extruded from the T-die to extrude a resin film for a diaphragm of a portable device speaker into a strip shape. As the single-screw extruder, the same single-screw extruder as in Example 1 was used. The temperature of the single-screw extruder was adjusted to 350 to 365 ° C., the temperature of the T-die was adjusted to 365 ° C., and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 365 ° C. Further, regarding the temperature of the molten molding material, it was decided to measure the resin temperature at the inlet of the T die, and the measured temperature was 372 ° C.

Once the resin film for the diaphragm of the portable device speaker is obtained, the film thickness, mechanical properties, slipperiness, acoustic properties, and winding wrinkles of the resin film for the diaphragm of the portable device speaker when wound on the take-up tube. It was decided to measure the occurrence of the above, list it in Table 4, and evaluate it.

[Rating]
In the case of each example, since the adhesive fluororesin was added to the crystalline thermoplastic polyimide resin, the loss tangent at 20 ° C. of the resin film for the vibrating plate of the portable device speaker increased to 0.015 or more, and resonance occurred. I was able to obtain good quality sound quality characteristics. In addition, since it was prepared with a crystalline thermoplastic polyimide resin and an adhesive fluororesin, sufficient slipperiness can be obtained by lowering the coefficient of static friction and the coefficient of dynamic friction, and a resin film for a vibrating plate of a portable device speaker can be obtained. It was possible to prevent wrinkles from occurring when winding the film on the winder.

Further, since the tensile elastic modulus is 1000 N / mm ² or more and 3000 N / mm ² or less, the handleability of the resin film for the diaphragm of the portable device speaker is good, and there is no problem in molding the portable device speaker. Furthermore, it was confirmed that in addition to the treble characteristics, excellent bass characteristics and good sound quality characteristics that suppress the occurrence of resonance can be obtained.

On the other hand, in the case of Comparative Example 1, since the adhesive fluororesin was not added, the coefficient of static friction and the coefficient of dynamic friction of the resin film for the diaphragm of the portable device speaker became high and large, and the loss tangent at 20 ° C. was 0.013. It was as follows. As a result, when the resin film for the diaphragm was wound around the winder, wrinkles were confirmed, the occurrence of resonance could not be suppressed, and good sound quality could not be obtained.

In the case of Comparative Example 2, since 150 mass was added to 100 parts by mass of the crystalline thermoplastic polyimide resin, the tensile elasticity of the resin film for the diaphragm of the portable device speaker was less than ^{1000 N / mm 2.} , The handleability of the resin film for the vibrating plate of the portable device speaker was poor, and there was a problem in the moldability of the portable device speaker.

In the case of Comparative Example 3, the resin film for the diaphragm of the portable device speaker to which the PFA resin, which is a fluororesin having no adhesiveness, was added, had a loss tangent at 20 ° C. of 0.014 or less. As a result, the occurrence of resonance of the resin film for the diaphragm of the speaker of the portable device could not be suppressed, and good sound quality could not be obtained. Furthermore, in Comparative Example 5 and Comparative Example 4, since a thermoplastic polyimide resin of the amorphous, tensile modulus of greater than 3000N / mm ^2, causes increased also F ₀ value, the deterioration of the bass characteristics I couldn't prevent it.

The resin film for a diaphragm of a portable device speaker and a method for manufacturing the same according to the present invention are used in the manufacturing fields of mobile phones, mobile game devices, smartphones and the like.

1 Resin film for diaphragm 2 Molding material 3 Elastomer layer 10 Melt extrusion molding machine (extrusion molding machine)
13 T dice (dice)
17 Crimping roll 18 Cooling roll 20 Winding machine

Claims (5)

It is molded from a molding material containing 100 parts by mass of a crystalline thermoplastic polyimide resin and 1 part by mass or more and 100 parts by mass or less of an adhesive fluororesin, and the thermoplastic polyimide resin contains at least a tetracarboxylic component and an aliphatic diamine. It is prepared with the main component diamine component,
The maximum tensile strength at 23 ° C is 40 N / mm ² or more, the elongation at tensile break is 100% or more, the tensile elastic modulus at 23 ° C is 1000 N / mm ² or more and 3000 N / mm ² or less, and the coefficient of static friction at 23 ° C is 0.50. A resin film for a diaphragm of a portable device speaker, which has a dynamic friction coefficient of 0.50 or less and a loss tangent at 20 ° C. of 0.014 or more. When an elastomer layer having a thickness of 10 μm or more and 100 μm or less is sandwiched between a pair of resin films for diaphragms, and the durometer hardness of the elastomer layer is measured by durometer type A in accordance with JIS K 6253, The resin film for a diaphragm of a portable device speaker according to claim 1, which is A10 or more and A90 or less. The resin film for a diaphragm of a portable device speaker according to claim 1 or 2, wherein the diamine component of the thermoplastic polyimide resin is a linear aliphatic diamine having 4 or more and 12 or less carbon atoms. The portable device speaker according to claim 1, 2 or 3, wherein the apparent shear viscosity of the adhesive fluororesin at 350 ° C. is 1 × 10 ² Pa · s or more and 1 × 10 ^{5 Pa · s or less when a load of 50 kgf is applied.} Resin film for diaphragm. The method for manufacturing a resin film for a diaphragm of a portable device speaker according to any one of claims 1 to 4.
A molding material is prepared from 100 parts by mass of a crystalline thermoplastic polyimide resin and 1 part by mass or more and 100 parts by mass or less of an adhesive fluororesin, and the thermoplastic polyimide resin of this molding material is mixed with at least a tetracarboxylic component and an aliphatic component. Diamine is the main component of the diamine component
The molding material is melt-kneaded and put into an extrusion molding machine, and the molding material is extruded into a resin film for a diaphragm of a portable device speaker by a die of the extrusion molding machine, and the resin film for the diaphragm is brought into contact with a cooling roll. A method for manufacturing a resin film for a diaphragm of a portable device speaker, which comprises winding the cooled resin film for a diaphragm on a winder.

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